Introduction of Advanced PhotoDetector - Quantum Efficiency System(APD-QE) Original link：https://enlitechnology.com/home/products/photo-detector-testing/apd-qe/ *About Enlitech Enlitech was founded in March 2009. The core technologies include artificial light source and spectrum analyzing technique.Enlitech’s four main product markets include image sensor testing solutions, advanced photoelectric detector testing systems, quantum efficiency test solutions, and various light simulators. Our popular products are QER and SS-X solar simulator. If you are interested, please visit the official website to understand more! https://enlitechnology.com/

1. Enli Technology Co. Ltd.
December 9, 2021
1
Introduction of Advanced PhotoDetector -
Quantum Efficiency System(APD-QE)
The Cutting-edge tool for the cutting-edge photodetectors

2. 2
Basic Introduction
• With the rise of 5G technology and popularization mobile devices, more and more
advanced photoelectric sensors are used in our daily lives. In order to be better
applied to mobile devices, the photosensitive area of these advanced photodetector
is getting smaller and smaller. However, these applications place higher and higher
requirements on the light sensing performance of advanced photodetectors. In the
process of shrinking the photosensitive area, it also brings the challenge of accurate
measurement of quantum efficiency. For example, under different wavelengths of the
traditional focused beam spot, the focal shift caused by the dispersion of different
wavelength can reach mm-level. It is difficult to focus all photons into the micrometer-
level active area. Therefore, it is hard to accurately measure the full-spectrum
quantum efficiency curve.
• APD-QE adopts the spatial light homogenizing technology and follows the
ASTM standard “Irradiance Mode” test method, which is proven that it can
accurately perform quantum efficiency and other key parameter measurements
of advanced photodetectors.
• APD-QE can combine with various advanced probe stations to deliver a complete
testing solution for many advanced photodetectors, such as iPhone LiDAR and a its
variety of light sensors, Apple Watch blood oxygen light sensor, TFT image sensor,
active active pixel sensor (APS), high-sensitivity indirect conversion X-ray sensor, etc.

3. 3
Basic Introduction
• Challenges of traditional QE systems in the testing of new photodetectors:
1. Most of the quantum efficiency systems on the market are “Power Mode.”
2. With the widespread popularity of mobile devices, advanced photodetectors
such as APD, SPAD, ToF, etc., have miniaturized the light-receiving area of the
device. The effective light-receiving area ranges from tens of microns to
hundreds of microns (10um ~ 200um).
3. The “Power Mode” focusing light beam is hard to accurately measure the
advanced small-area photodetectors due to :
• It is difficult to completely focus all photons into the effective light-receiving
area in micrometer level (cannot meet the requirements of the Power Mode)
=> The absolute EQE is hard to be get.
• It is difficult to overcome measurement errors caused by optical dispersion
and spherical aberration when focusing different color of light. =>The EQE
spectrum curve is incorrect.
• Difficult to integrate probe stations.

4. 4
Contents
 Features
 System Design
 Specification
 Application

5. 5
Features
• Uniform light beam spot (“Irradiance Mode”) which complies conforms to ASTM
E1021
• Uniform light spot can overcome the problems of chromatic dispersion and
aberration, which can accurately, compared to traditional focused beam spot,
measure the EQE curve of micrometer-level photodetectors
• It can be matched with a variety of probe station systems to achieve non-destructive
and rapid testing.
• The integrated optics and test system improve the efficiency of system construction.
• One-key automatic test software, automatic full spectrum calibration and
measurement, high work efficiency.
• Test characteristics:
– External quantum efficiency EQE
– Spectral response SR
– I-V curve measurement
– NEP spectrum measurement
– D*spectrum measurement
– Noise-current-frequency response graph （A/Hz-1/2; 0.01Hz~1,000Hz）
– Flicker noise, Johnson Noise, Shot noise analysis

6. 6
System Design

7. 7
Specification
Main system
Quantum Efficiency Testing 300nm ~ 1100nm
(expandable to 2500nm)
Software
PDSW software
Upgradable to FETOS-SW (3T or 4T
Probe station system (option) 4” standard probe station (MPS-4-S)
Customized integration solution
combining probe stage and
dark box.

8. 8
Specification
Integration of Uniform Light Homogenizer and Probe Station

9. 9
Specification
Integration of Uniform Light Homogenizer and Probe Station
The use of the exclusive patented Fourier optical elements to form homogenization
system can uniformize the spatial distribution of the monochromatic light intensity. The
light intensity distribution is measured at 5 x 5 matrix in an area of 10mm x 10mm, and
the un-uniformity is less than 1% at 470nm, 530nm, 630nm, and 850nm. When
measuring the light intensity distribution with a 10 x 10 matrix in an area of 20mm x
20mm, the unevenness can be less than 4%.

10. 10
Specification
PDSW Software
PDSW software uses the new SW-XQE software platform, which can perform a variety of
automated measurements, including EQE, SR, I-V, NEP, D*, frequency noise current
graph (A/Hz1/2), noise analysis, etc.

11. • PDSW Software
 EQE Test：PDSW software can test
wavelength of different monochromatic
light and automatically perform EQE
test for full spectrum.
11
Specification
 I-V Test：The software supports a
variety of SMU controls, automatic light
I-V test and dark state I-V test, and
supports multi-data display.

12. • PDSW Software
 D* and NEP：Compared with other
QE systems, APD-QE can directly
measure and obtain D* and NEP.
12
Specification
 Frequency-Noise Current Curve

13. • PDSW Software
 Upgradable Software：Software can
upgradable to FETOS software which
can characterize 3-terminal or 4-
terminal devices.
13
Specification

14. Integration with Probe Station
APD-QE system can combine many kind
of Probe stations due to its outstanding
optical system design. All the optical
components of full-wavelength
spectrometer are integrated in the
compact system. The monochromatic light
is guided from spectrometer to the probe
station shielding box. The picture shows
MPS-4-S basic probe station components
with 4” vacuum chuck and 4 probe micro-
positioners with low noise triaxial cables.
14
Specification
The microscope of probe station is
integrated and be switched to the position
of the device under test with manual
slider. The monochromatic light
homogenizer is “pinned” at the designed
position after using slider bar. The
microscope image can be displayed on
the screen which is convenient for users
to make the good contact.

15. Customized Integration Solution Combining Probe Stage and Shielding
Dark Box
A. Customized Shielding dark box.
B. Advanced Photodetector usually needs fast response response time.
Therefore, the active area is usually small which requires probe station
to make electrical contact.
C. Ingegratable with different semiconductor analyzer such as 4200 or
E1500. 15
Specification

16. 16
Application
1. Optical sensor in LiDAR
– InGaAs Photodiode/ SPAD
2. Photosensor of APPLE Watch
3. Photodiode-gated Transistor for high gain sensing and imaging
4. High Photoconductivity Gain and Fill-Factor Optical Sensor
5. Highly-sensitive indirect-conversion X-ray Detector characterization
6. Silicon Photonics

17. 17
Application
Application 1: External quantum efficiency of Photodiode in iPhone 12’s
LiDAR and other sensors

18. 18
Application
Application 2 : External quantum efficiency of Photodiode in Blood
Oxygen sensor of APPLE Watch 6
The new Apple Watch Series 6 comes with a blood oxygen sensor and an accompanying
app to give you more ways to monitor your heart and respiratory health.
The blood oxygen sensor is built into the back of the Apple Watch. It uses four sets of
red, green and infrared LED lights and four photodiodes, these devices can convert light into
electric current. The light hits the blood vessels on your wrist, and the photodiode measures
the amount of light reflected back. Basically, oxygenated and deoxygenated blood absorb red
and infrared light in different ways, so the reflected light allows Apple Watch to determine the
color of your blood.
APD-QE system is adopted to study and analyzing
photodiode in blood oxygen sensor including visible and
infrared wavelength range.
APD-QE can provide the information of these
photodiode:
1. External quantum efficiency (300nm ~ 1700nm)
2. SR (A/W)
3. NEP and D*
4. Frequency-Noise curve（A/Hz1/2）
5. Noise Type

19. 19
For more applications of APD-QE, please click on the
following link:
https://enlitechnology.com/home/products/photo-detector-testing/apd-
qe/

20. Thank you for your
time and
attention.
ENLITECH CONFIDENTIAL
20

21. 21
ENLITECHCONFIDENTIAL
• R&D and Production of Quantum Efficiency/
Spectral Response/IPCE Measuring Equipment
• Image Sensor/Photodiode/Semiconductor Testing System
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• Innovative R&D/Technology Integration/Total Solutions
for Customers
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Headquarter:
ADD/ 1F., No.96, Luke 5th Rd., Luzhu Dist.,
Kaohsiung City, Taiwan (Kaohsiung Science Park)
TEL/ +886-7-6955669
Email: qeservice@enli.com.tw
Shanghai Branch:
Room 5I, Block 3, No.100, Lane 1505, Zu Chong Zhi Road,
Pudong New District, Shanghai, China
TEL/+86-21-31338780 / 18512186724